Chuck



May 2, 1933. s. w. PARSONS ET AL CHUCK Filed'Sept. 17, 1930 Stuart W Parsons Guszaue I? Dab/mar? .ment,-"the-chuck is providedwith a socket in which is; seated a block formed witha pair of Patented May 2,1933.

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, A conrolmrron or'commcrrcur,

Application ,naeaise tember 1r, saucer-141mm t n. that tool shanks Fare I often provided at,

- theirj ends with a non-circular or square poritionwhich is received in, and engaged by, the chuck. It is desirable that the shank; in addition to being positively held against re- .tationint'he chuck, be supportedina-positive and rigid manner in order that it is properly centered and well steadied against lateral or wobbling movement to efiect amore accurate Operation J 1 1. k

Bearing the foregoing in mind, this inven tion 'has,1-as an important object, the proivisionof a chuck including jaw elements which are movable to grip the rounded portion of a, tool shank, and which also includes means independent of the jaw elements for iengaging with thesquared end of the tool shank to prevent "rotation of the latter. More particularly, the :main'body of the chuck is formed with shoulders Which'enp m part-pointed out more indetail herein- I gage with thefiat surfaces of the squared end to inhibit the. turning movement. In carrying outthis thought in a practical embodicomplemental steps which imparts to the 35 chuck. head the capability; of accommodating and holding the squared end, of tool shanks ,of v varying sizes. 7

further aim ofthe invention is them 1 ,vide a chuck of the character described which is more or less universal in its natureinthat constructionfsizes and shapes. More' particularlyythe arrangement is such that a tool having a shank of; suflicient length may be held at the, squared end in saidsocket-and supported at its round portion 'betweenthe jaw faces of saidmovablejaws, and a tool, such as streamer, having an adjustable feature so located that the shank cannot bep0--:

sitioned between the. jaws with thesquared end in the sockeumay be secu ely held by practice is accompanied with certainimanui Viacturing -.d isadvantages in ;that the parts must b very" accurately machined; and 11s 7 therefore departed from by the present in- :v-enti'on which provides separate means for prevcnting this'relati've turning jamoven ent ion" thef pa rtoftthe jaw elements. -:'In the and intothe grooves in the'jaws whereby-rel? atarelatively low-cost. g

fi 1;-$ 0 ndv escope of the. applica ltion f wh w l, be indicated ;in the Zappendedclaims" v I it is adapted-tohold tool 'shanks of various v v j I {Fig.1 is a view in side elevation of a chuck embodyingthe improvements of this inven-x I flboub 0n the plane indicated by the line 3+3 the movable jawsthemselves grippingon .ho 1ding the short squared endof the shank. I Ordinarily the jaw elements of the chuck are operatively mounted in the head and suitable: means are provided foroperating the aw elements. Heretofore it has bjeeritlie practice to also avail of th-isjoperating means as the 1 means; for preventing rotative move ment ofithe jawelements in the head. Thisv present embodiment, the jaw elernents a e provided 'with grooves which receive v spline members projecting inward-1y from the, head. 6

ative lateral or radial movement of'the jaw -.elements is permitted, while turning move- .ment is prevented. These, spline members arejof novel-and simple construction, which permits their embodiment in the. chuck head Other objects will be in par-tobvious,and}

after. w j The-invention accordingly consists in the l features-of construction, combination of elements and arrangement ofgparts'. which will b ..iexempliified in the. construction herein- I fthe accompanying drawing, wherein we have shown, forgillustrative' purposes, one

embodiment which the. present invention {)0 m ke;

. f Fig.3 isasec'tion taken at right, angles to the showing of 'Fig.:.-1. 11 This .view is taken which are Fig. 4 is a View in side elevation of one of the jaw elements per se;

Fig. 5 is a view in end elevation of the aw element shown in Fig. 4;

Fig. 6 is a view of the'jaw element in longitudinal section, this -view being taken on line 6.6 of Fig. 5; and

Fig. 7 is a detailed View showing the manner in which a tool having a relatively short, round shank is held between the radially movable jaws themselves.

Referring now to the drawing, the main body or head of a chuck is designated 10. This head may be of a cylindrical formation as shown and is provided with an opening 11 which extends axially through the cylindrical portion of the head 10. The latter is reduced at one end as indicated at 12, and this reduced portion is provided with a bore 13 which is threaded as indicated at 14 so as to provide means for operatively mounting the chuck on the spindle of a machine, such as a reamer, lathe, or other similar mechanism. It is to be understood that the chuck head may, of course, be mounted in any other approved manner, the illustrated construction being merely one method of accomplishing this end. 7 i

The opening 11 terminates in a socket 15 which extends into the reduced portion 12. Detachably mounted in the socket 15 is a block 16 which is provided with'two series of steps indicated at 17 and 18. The block 16 is held in position in the socket 15 by a screw, designated 19, having a pointed end, asshown at 20, and which is spotted in a complemental opening in the block 16. Any suitable means for operating the screw plug may be availed of, such as the non-circular opening shown at 21. The series of steps 17 and 18 are of duplicate construction and the plane surfaces constituting each series of steps are either in alignment with, or parallel to, the corresponding plane surfaces of the other series. Moreover, the steps are disposed at a substantially right angular relationship with respect to one another. In other words, the front face of the block 16 has a ninety degree V-groove the sides of which are correspondingly stepped so as to provide a plurality of pairs of, opposed shoulders the planes of which are parallel to the axis of the chuck, and the successive pairs of shoulders are spaced at successively greater distances from the center of the chuck. The tool shank shown in Fig. 3 and having .a-cylindrical portion 22 and a squared end 23 is typical of a tool shank which is intended to be gripped by the chuck hereof. When the shank is properly positioned in the chuck head, the'squared end 23 will be seated in, and engaged by, the stepped arrangement 17 and 18 on the block 16. The plane surfaces perpendicular to the axis of the head partially engage the end surface of the sides of the squared end in an obvious manner. The stepped arrangement provided imparts to the chuck the capability of accommodating tool shanks of various sizes. The mere insertion of the shank in the head will insure the engaging of the squared end with the perpendicular plane surfaces of the stepped arrangement.

The head 10 is provided with an opening 2 1 which extends diametrically across the head in a transverse direction with respect to the opening 11. A second smaller opening or hole 25 extends chordally across the head 10 and communicates with the opening 24. Intermediate the ends of the opening 25. the head is formed with a rib 26 which provides a surface 27 that constitutes a journal, as will be hereinafter pointed out in detail.

A screw member, designated generally 30, is located in the opening 25 and has screw sections 31 and 32 atits opposite ends and an intermediate reduced portion 33 which is journaled on the surface 27. The reduced construction between the screw sections 31 and 32 provides shoulders which straddle the rib 26 whereby the screw member 30 is maintained in proper position in the head. The threads on the sections 31 and 32 are respectively left and right handed. The screw member 30 may be provided at each end with any preferred type of wrench engaging means such as a non-circular socket shown at as.

A pair of jaw elements 35 and 36 are operatively mounted in the opening 24- and are atsections 31 and 32 and having teeth or thread sections corresponding to, and adapted to cooperate with, the threads on said screw member. Heretofore it has been customary to rely upon the interlock set up by the engagement between the screw member 30 and the panels on the jaw elements for preventing rotation of the jaw elements in the chuck head. This practice is attended with certain disadvantages, includ' ing the necessity of machining the parts with a very high degree of accuracy in order that they closely fit while permitting movement therebetween, and not infrequently the jaws become cramped and not easily operable. In accordance with the present invention, the screw member is relieved, to a large extent, of the function of preventing rotation of the jaw members, and to this end there is provided a spline and groove arrangement between the jaws and the chuck head. This spline arrangement insures correct alignment respective groovesof' the jaws;

present instance, this improved arrangement includes a longitudinally extending groove 9 in each j aw element diametrically opposite i-the thread panel 37 thereof, and keys 28 can ried by the chuck head and engaging inthe The keys '28 are located in slots 29 cut in the chuck head atfthe ends of the opening24 and diametricallyopposite to the-screw member-30; These-slots are preferably formed. by millinglthem with a cutter, an operation which may be easily andquickly effected. Thekeysjare in the form of sectors. One

, straight edge of eachkey projects into the opening 24, and theperipheral edge of each is curved corresp ondi-nglyto, so as, to register I with, the external .peripher Z of the chuck body.- The other edge of eac sector engages against the .bottom of the respective slot 29.

InFig. 1, th'e edgesof the key are illustrated more or" less prominently in order-to show the structure, but in actual practice theseedges will hardly beperc'eptible as the curved surface ofthe key is al-ignedwith, and merges into, the curved periphery of the'chuckrbody. The keys may bBlSBCHXBCl in'place by :cross ins 28",, L v I c I I Each of the jaw elements is provid ed, on its inner end, withtwo series of ribs, prefer-' ably arranged in staggeredrelation. The'inneror opposed surfaces of the ribs are relatively inclined so as to provide, in effect, a pairof jaw faces which areatiright angular relationship with respect to one another. In the drawing, the ribs of one series aredesig-v. nated by the numeral 38, and those of the other series by the-numeral 39. The inclined and opposed surfaces of these ribs are indi cated by the numeral40. The surfaces 40 on each series of ribs are at an angle of forty-five degrees with respect to the axis of the aw element, which means that the angle between the opposed surfaces ninety degrees. When a tool having an unobstructed round shank,

l such as shown in Fig. 3,'is to be gripped, the

faces 40 of the ribs engage and rigidly hold the round portion of the shank, while. the stepped arrangement 17 and 18 engages. the squared portion of the shank and prevents rotation of the shank while itrisbeing held inthe head. I

In order to increase'the range ofutility of the structure described and adaptit for use in connection with tools of various'kinds. and sizes,the staggered arrangement of the ribs 38 and 39 terminates short of the forward edge of the jaw faces of the elements, and ad acent these forward edges there is provided a V-shaped groove having at each side an unbroken face 41, the faces beingdisposed at'ninetydegrees to one another. In effect,

. these faces 411 ofthe Vsgrooveare provided onlthe opposed faces ofprojections 4-.2direotlesser height than the staggered ribs .38 and 39. With this arrangement, f a tool shank Ily'opposed and located forwardly: of .and1of I such as shown in Fig. 7 may besecured'in the r chuck. That shank may comp-rise theend of Ta reamer of a well knownsorthaving adjust-1 I able blades which are adapted to be adjusted 'or locked in position :by a, knurled nuti43 threaded onto the shankfiv Ordinarily,.-1the; "distance betweenthis knurled vnut'and the squared end 44 of the shank is not suficiently great to permit the j awsto engage the round shank rearwardly r 0f the nut when the squared end is engaged with the stepped block; In such instances, .the' squared end 'of "the shank may be engaged and securely held against turning movement'by grip-ping it between the jaw surfaces 4:1,as illustratedin Fig.7;

Briefly outlining the mode of operation of the foregoing construction, whena'tool having a shank, such as shown in Fig.3, is to be secured in place, the screw'element is rotated to "separate the jaw elements sufliciently to permit of ready insertion of the tool shank. The squared end of the latter is'now inserted through the opening 11 and the j aw elements, and .is engaged -with the properplane "surfaces of the steps 17 and 18. Thescrew mem- 'ber: 30 is'now rotated in the proper direc tion by appropriate wrench. means, whereupon the jaw elements are movedinwardly to cause theribs 38 and '39 on the jaw faces to grip the round portionof the shank. The shank is now heldsecurely againstturning movement by the engagement of a squared a I portion inthe block '16, and is securely held, 1

the opposed jaws 35- and 36.1 When thetool 'isof suchconstructionthat its shank cannot I be engaged as. justdescribed, aslwhenythe shankhas anut 43located as shownin Fig. 1 I

against lateral, and wobbling movement by 7, the squared end of the shank is engaged between the gripping surfaces at theforward ends 7 of the j aw "faces and is I held ,the'reby against rotary movement relativeto the chuck.

. .Infdevising foregoing chuck ass m y? body.v

simplicity of construction, reliability, and

-positivenessof operation, as well as ease and economy of manufacture, have been para mount features which were borne in mindand whichcontrolled the designingof this chuck mechanism. The arrangement of the jaw elements in the head insures easy, accurate, and

positive operation of the jaw elements inthe head under the influenceof the screw mem-r ber 30, while. construction oflthe jaw faces makes certain of a good gripping engagement,

with the rounded portion of the tool shank in one instance,'or withjthe squaredend ofthe shank, inthe other instance.-

By providing" above construction and many apparently widely diiferent embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or -shown in the accompanying drawing shall be iting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. In a chuck of the character described, a head having an axial opening and a cylindrical opening transverse to said first mentioned opening, the head also having a cylindrical hole parallel to and communicating with the transverse opening, generally cylindrical jaws radially movable in said transverse opening and having thread panels, a round screw member in said hole having screw sectionsengaging said panels, means for operinterpreted as illustrative and not in a limatingthe screw membeneach jaw having a longitudinal groove formed therein, said head having at each end of said transverse opening a slot extending from the periphery of said head to the wall of said transverse opening,

and a key secured in each slot, each key having an edge projecting into said transverse openying and received by one of said grooves, the

outer faces of said keys being curved corre sponding to and being flush with the peripheral face of'said head. 7 j

a 2; Achuck of the character described comprising a rotatable chuck head, a pair of aligned jaw elements radially movable in the head, the inner end of each jaw element having two series of ribs disposed on opposite sides of the transverse center of said end, the

ribs of one series being staggered with respect to the ribs of the other series, the opposed faces of said ribs beingoppositely inclined, said staggered ribs terminating short ofthe forward edge of the jaw faces, the inner end of each of said elements forwardly of said staggered ribs having projections directly opposed and of lesser height than the staggered ribs, the opposed faces of said projections being inclined relative to one another and forming a V-groove.

3. A chuck adapted to receive bits of va- IlOllS slzes, comprising a rotatable chuck height than the ribs, said chuck head having a socket inwardly of said jaw elements, and a block secured in said socket, the outer face of said block being recessed with two series of opposed steps therein providing plane surfaces at diflerent radial distances from the axis of the head and adapted to engage the square ends of tool shanks.

4. A] chuck adapted to receive bits of varioussizes, comprising a head having an axial opening and a cross opening transverse to the axial opening, generally cylindrical jaws radially movablein said transverse opening and having thread panels, a round screw membermounted in the head having opposed screw sections engaging said panels, each jaw having a longitudinal groove formed therein. a key mounted in the head at each end of the transverse opening and engaging in the groove of the adjacent jaw, said head having a socket at the inner end of said axial open in g beyond the jaws, a block secured in said socket and having a diametrically extending groove with inclined walls which are stepped to provide plane surfaces at different radial distances from the axis of the head to en "a we the square endsof tool shanks. b a

STUART W. PARSONS. GUSTAVE R. DAHLMAN. 

